| Square | … |
|---|---|
| A square. The blue ∟ annotations mark equal right angles at its vertices and the red // annotations mark equal side lengths. | … |
| Type | • quadrilateral • regular polygon • hypercube • cross-polytope |
| Edges and vertices | 4 |
| Symmetry group | order-8 dihedral |
| Area | side |
| Internal angle (degrees) | π/2 (90°) |
| Perimeter | 4 · side |
(echo:: @ ᯤ)